Getting a handle on winter
HANCOCK – Precipitation totals for October and so far in November may be at or below historic levels, but that isn’t necessarily a precursor of what the coming winter will be like, according to the National Weather Service office in Negaunee Township.
Justin Titus, meteorologist with the NWS, said forecasting for the entire winter in the Keweenaw is difficult because there are many variables which can’t be accounted for. However, so far the coming winter doesn’t look like snowfall will be significantly on the lower or higher.
“This winter, there’s no strong indication it will be above or below normal,” he said.
Titus said most snowfall in the Keweenaw comes from lake effect systems, and they can appear with little or no warning.
“(Snowfall amounts are) so dependent on smaller scale features,” he said. “They can change fairly regularly.”
Those smaller features include wind speeds and temperatures of the air and the water in Lake Superior. Cold air passing over the relatively warmer lake can lead to lake effect snow.
A lake effect system started Friday and continues today with areas in the higher elevations getting most of the snow.
“We’re expecting periods of heavy snow,” he said. “It’s going to be a sudden jolt into winter weather.”
Over the past 10 years or so, the first heavy snowfalls didn’t arrive in the Keweenaw until late December or even mid-January, and Titus said long-term residents who think that means the winters are changing are really remembering how winters were in the 1980s and 1990s, when snowfalls were especially high in early and mid November.
“We had many years of really hard winters,” he said.
Jonathan Voss, forecaster with the NWS Negaunee Township office, said in many Copper Country communities, rainfall for October was at or below historic averages for the month. Some areas were above normal. For example, the normal rainfall for Copper Harbor in October is 3.21 inches, but only 1.9 inches fell this October. In Ontonagon, the normal rainfall for October is 3.5 inches, but this year, it received 4.4 inches.
Whatever the rainfall totals are for autumn doesn’t have much affect on vegetation growth for the following spring, according to Mike Schira, Michigan State University Extension district educator in Hancock.
Schira said autumn rainfalls may affect wetlands, whose levels could rise or fall depending on rainfall amounts. However, it doesn’t have much to do with vegetation growth.
“Our growing season is more impacted by snowfall than fall rain,” he said.
The amount of snowfall an area gets can affect the number and intensity of wildfires in the spring and summer, Schira said. In 2012, there were many wildfires in the eastern end of the Upper Peninsula.
“They didn’t get much snow, so it didn’t pack the vegetation down,” he said.
Titus said besides the possible heavy lake effect snowfall this weekend, temperatures will be well below normal. In most of the Keweenaw, the low tonight will be about 12 degrees with windchills from 0 to minus 5 or minus 10. The highs Sunday should be about 20 degrees, but windchills could be from 5 degrees to 0.